Mechanical properties of N80Q steel pipe repaired by carbon fiber reinforced epoxy resin composites

In order to investigate the repair effect of carbon fiber reinforced epoxy resin composite on the ring-corroded N80Q steel pipe, the mechanical properties of the repaired steel were studied by numerical analysis and full-scale blasting test. The effects of axial length, depth and repair layer thickness on the repairing effect were analyzed. The results show that the carbon fiber/epoxy composite has a remarkable effect on repairing the N80Q steel pipe and the bursting pressure value of the 6 mm deep defect pipe is raised by 0.985 times after repaired by the carbon fiber/epoxy composite; the axial length of the defect has little effect on the strength of the N80Q steel pipe after repaired by the carbon fiber/epoxy, and as the axial length of the defect increases, the pipe burst pressure value only gets reduced by 3.5%; the depth of the defect has an obvious effect on the strength of the N80Q steel pipe after repair:Compared with the non-defective pipe, the burst pressure value of the 6 mm deep defect pipeline is reduced by 9.9%, and the burst pressure of the 7 mm deep defect pipe is reduced by 20.6%.